Pcx Yuminashi Chainsaw 164!

[Pcxdemon]

Hi all!

Finished with the pipe with this.
Looks shitty, 2-piece construction with some internal imperfections, but with a perfect shape. I have to add one more wide bracket in the middle for sure.
Just tired searching for this 50mm pipe around, may be later I will see it somewhere and cut

Heh, today I am planning to take the scooter back home, have to ride thru clouds of dirt, snow, ice, water,etc.. The temp outside is around zero.

To polish the swingarm you have to use the sandpapers with different grits, then polishing with pastes like dialux. Motocross people do polish the bike's frames, so they know how.
I did a engine head porting to fit Yuminashi intake manifold, and polished all the inner surfaces to a mirror too

So here was a tons of work with the bike, and I am highly excited to try it out!

I'd love to fit 150 intake valve in my 125 head and polish just the exhaust port...
I have a yuminashi intake manifold which is mirror polished inside but it has same port diameter as the head intake port. Is yours actually bigger than the port?

[Reaper]

I'd love to fit 150 intake valve in my 125 head and polish just the exhaust port...
I have a yuminashi intake manifold which is mirror polished inside but it has same port diameter as the head intake port. Is yours actually bigger than the port?

I shaved around 1mm from the sidewall, so the head intake channel was 2mm less diameter than the Yuminashi intake manifold. May be RZracing modified the intake parts from Yuminashi,
he told me that he had to shim manifold surfaces to make them perfectly flat, I suppose Yuminashi parts are coming not perfectly made sometimes, I don't know. May be RZracing enlarged
the channels in Yuminashi parts to fit their 190cc kit, I don't know. As for today I just don't remember the exact intake diameter what I have for today.

I had a ride back home yesterday on a bike, and it was a real extreme with around freezing temperatures outside. I liked how the bike performs, it felt totally different than it was.
I used just 1/4 of throttle for break-in , and with such low outside temps I suppose the ecu was out of fuel enrichment corrections, and this run was with lean afr. The engine sounded right, except the idling. The idling was high and unstable.

But, after keeping the bike for 2 hours at +20C in my garage, I started the engine again, and the idling stabilized itself to perfect!

Now I am praying for just one warm day to push this bike harder in soon

[Pcxdemon]

I'd love to fit 150 intake valve in my 125 head and polish just the exhaust port...
I have a yuminashi intake manifold which is mirror polished inside but it has same port diameter as the head intake port. Is yours actually bigger than the port?

I shaved around 1mm from the sidewall, so the head intake channel was 2mm less diameter than the Yuminashi intake manifold. May be RZracing modified the intake parts from Yuminashi,
he told me that he had to shim manifold surfaces to make them perfectly flat, I suppose Yuminashi parts are coming not perfectly made sometimes, I don't know. May be RZracing enlarged
the channels in Yuminashi parts to fit their 190cc kit, I don't know. As for today I just don't remember the exact intake diameter what I have for today.

I had a ride back home yesterday on a bike, and it was a real extreme with around freezing temperatures outside. I liked how the bike performs, it felt totally different than it was.
I used just 1/4 of throttle for break-in , and with such low outside temps I suppose the ecu was out of fuel enrichment corrections, and this run was with lean afr. The engine sounded right, except the idling. The idling was high and unstable.

But, after keeping the bike for 2 hours at +20C in my garage, I started the engine again, and the idling stabilized itself to perfect!

Now I am praying for just one warm day to push this bike harder in soon

Well when you get a chance with weather and it's run in a bit, you could make a short vid of the acelaration from 0-100 and post it on YouTube..
On another note, does it say anywhere about using 10% ethanol for Pcx fuel? Would it be safe on internals? I just filled my car with e10 unleaded and there is a noticeable difference in performance..

[Reaper]

Well when you get a chance with weather and it's run in a bit, you could make a short vid of the acelaration from 0-100 and post it on YouTube..
On another note, does it say anywhere about using 10% ethanol for Pcx fuel? Would it be safe on internals? I just filled my car with e10 unleaded and there is a noticeable difference in performance..

When I took the pcx for rent in Thailand, they said I can fill in the gasohol (ethanol-gasoline mix) no problem. Premium gasoline is 2 times more pricey than gasohol there in Thailand, so most people run their scooters on the gasohol mix.
In Russia we don't have any other fuel than regular or premium gasoline, so I can't test it's performance on e10 or e85 etc here..

As I know the idea of using ethanol/metanol is to cool down the combustion chamber temperature and low down the detonation (knocking) level.
When the ethanol injects and atomizes by the fuel injector, this proccess always comes with cooling and temp drop, you can feel this by your hand when spray any aerosol can.
So on ethanol mix the engine could run with more aggresive timing with a bit better performance. But, these modern fuels have less calories than usual gasoline so the fuel consumption will rise up.
IMHO the idea of using these type of fuels is for saving money first, not for the performance. May be, performance wize, it is good idea to run on ethanol mixes, in hot climate countries (as Thailand), where hot intake air could cause engine knocking.

The ethanol mixes are safe for fuel system internals, but methanol mixes are not! Fuel pump will die, all metal parts will rust and corrode, etc..

[Pcxdemon]

Got some goodies from webike...

I had to try a lighter clutch bell. Koso makes one that's 215g lighter than any other bell bar the NCY bell (60g lighter). It's one piece cast and it looks really good quality,also it has ribs on the outer of the bell for efficient cooling same as Malossi bell.
Also I got new ball bearings for the clutch spring. It's made by Advance Pro and it is really well thought of design. Much much better than Chameleon that offers one for sale as well.
Kitaco front brake pads..long time ago I've installed 260mm brake rotor but I've never replaced the pads though so I thought its a good time to get some nice performance pads to go with the bigger rotor.
Had to replace the 3 plastic variator plate guides, old ones were worn. So I got a set from Kn Planing and MFR brand. I'm glad I decided to get to diff makes as the Kn Planing are smaller and don't fit the stock back plate but MFR fits perfectly. They were only $4-5 a set so no big deal..

[gia]

@pcxdemon,

How many miles (km) do you have riding with the 164cc? Do you have any probs. I would buy also a 164cc.

[Pcxdemon]

@pcxdemon,

How many miles (km) do you have riding with the 164cc? Do you have any probs. I would buy also a 164cc.

I've done about 2500-3000km since installing that kit. So far she is fine..

[gia]

Hi,

I would only install the 164cc light bore kit and the performance valve kit. Will this works? I need just more couple.

[Reaper]

Hello there! After half of a year of waiting I am on the road on my PCX190 !
The engine was build in october, and since that moment I had no chance to try it out. Yesterday I did a first trip in the city, the engine feels good, everything seems works perfect. Now I have to do some break-in for this 190cc engine, and only then I can push it WOT and show you some numbers and impressions.

I still have an issue with the decompressor, the engine starts hardly, idle stop doesn't work, I have no idea were the mistake may be. Will do a visit to another scooter service, to check the camchain installed properly or not. My mech swears he installed and checked everything right. I think that the takegawa cam is made out of OE spec and that's why it doesn't work fine with the decomp.

[Pcxdemon]

Hello there! After half of a year of waiting I am on the road on my PCX190 !
The engine was build in october, and since that moment I had no chance to try it out. Yesterday I did a first trip in the city, the engine feels good, everything seems works perfect. Now I have to do some break-in for this 190cc engine, and only then I can push it WOT and show you some numbers and impressions.

I still have an issue with the decompressor, the engine starts hardly, idle stop doesn't work, I have no idea were the mistake may be. Will do a visit to another scooter service, to check the camchain installed properly or not. My mech swears he installed and checked everything right. I think that the takegawa cam is made out of OE spec and that's why it doesn't work fine with the decomp.

Get stronger battery,like 200cca. Since ive upgraded mine to Shorai lithium 210cca no problems starting without decomp even with the 13.1 compression Yuminashi cam no decomp..

[Reaper]

Hello pcx people!
Today I blown my 190cc engine, dont know what happend, no boom no rattle, just a couple of loud explosions in the exhaust pipe and thats it. The engine turns over, but no start, seems it lost the compression.
What I didnt like on this engine- bad start, and it was running lean at full throttle even on map3 i-map. On mid-throttle afr was around 13-14, at full throttle 16. Heh, waiting to open the engine, opening will tell the truth.

[Valiant]

Did you install a larger fuel injector? Sounds like the lean mixture caused detonation, which blew up your engine.

[Pcxdemon]

Nooooo!! Yes going 16afr on wot will deff blow it!!

[Reaper]

Yes, I installed the larger injector, this bbk was purchased as a complete kit, so here is no mistake in the spec list. I didn't install anything myself, I asked a good friend of mine, a motorcycle mechanic with a good reputation, and he swears he did everything right. will see..

What I didn't like after the first engine start - on cold engine started after 3 or 5 try, so seems the decomp didn't work. We took off the valve cover, checked that decomp moves freely, checked the valve clearances, everything seemed right. After a negotiating with the engine designer, he advised me to change the exh valve clearance from .24 to .12. We did it, it helped a lot, but didn't solve the problem, still have no perfect start that pcx is famous about. I installed brand new OE honda yuasa battery, seems a bit better again but still not perfect, sometimes it cold starts 3 try, sometimes second try.

Ok, then it was a 6 month pause because of the winter. Last week I did a very first trip for 10kms to see what I have. It is a break-in period so I didn't push it wot. AFR was jerking around 12.5-13.5-14.5, mostly around 13 on half throttle, so it looked good.
Yesterday I did a 100km trip to break-in faster and opened a throttle step-by-step more and more, and noticed that when I push it full throttle (for a second or two), afr showed 16, that is WAY LEAN I clearly understand.
I tried to change the I-map settings from map3 to map1 and back to see what it changes, I noticed that I-map works, but... still 16 on wot.

We have a long straight bridge road in the city, may be 3 miles or so, a good place to check the engine I did the experiment to open the throttle little by little more, to find the point when the afr changes from 13 to 16, and when I reached 60mph (100kmh) I felt a great loss of power, engine stopped slowly, then 2 or 3 backfires in the exhaust and finish, I had to push my bike for an hour back home

Now quastions:
1. how to relate the bad engine start with the lean AFR 16 at wot? Might it be because the timing chain might be a tooth off ?
2. I will take off both enjectors to make them a capacity test, they are both same looking, so may be somehow I got the same OE injector, not the larger one, or may be my mech just forgot to change it or mistaken with it because they are the same looking?
3. Are the any marks on magneto/starter to check ? I mean is it real to make any mistake installing the magneto? I have no honda service manual, I get information over the internet there and there, and didn't see any regulations about the proper magneto installation.

I am afraid that when I rebulid the engine again ( I have no choice) I will get exactly the same issues.. Of course I will check myself everywhere I can.

[Valiant]

Was this a Yuminashi kit or from some other source?

Only thing I can think of is the injector(maybe didn't have enough flow), unless you have the new LED PCX model and tried to install a larger Throttle Body without rewiring the sensor block.

[Pcxdemon]

The possible reason for 190cc not wanting to start up correctly is most likely due to starter motor of the 125cc model is not powerful enough, I know that 150cc model has a bigger starter motor and it seems now that would be a must upgrade for 190cc kit.
Fuelling wise, I'd say with 98% confidence that using takegawa FiCon and bigger injector would solve that side of problems, however Reggy said there is new latest injector that will fix the fuelling on 190cc without need for piggy back controllers.

[Valiant]

I'm more interested in the supplier, as I believe only Roman from RzRacing offers the 190cc kit, and he also uses the Kitaco i-Map for it.

Little worried since he sent me my 175cc kit without the larger intake tube and the insulation piece for the 31mm manifold. He also didn't seem to know how to rewire the sensor block to work with the 2015 PCX wire harness.

Might bring up questions about his mechanical competence, as well as whether or not I should expect my 175cc kit to blow up the engine anytime soon.

[Reaper]

Thank you for replies, guys!
My scoot actually is a pcx150 2013, so the starter should be ok. I am pretty sure I got the improper capacity injector from the seller, I have to take it off, and do a flow test on the stand, for both, for OE and the larger one, to see the actual difference between them. That days half year ago I saw only one kind of larger injector on the market, today they offer 6-holes, 8-holes, 14-holes versions. My 190cc engine needs the 14-holes version, as I understand.

I have to open the engine first to see what's damaged and calculte the losses..

[Reaper]

As for mr.Roman, I think he is the best supplier/producer of the cylinders, pistons, cranks, etc.. We checked and measured everything here, all parts were made with the best. I am sure my engine blown not because of poor machining/measuring/overall quality of the mechanical parts. Here might be a human mistake with the wrong size injector he sold me. I know that he had to shim some of Yuminashi parts special for me because of unstable quality of the Yuminashi intake parts, he made in for free btw. Hmm.. I am not that kind of people who screaming everywhere about how bad the sellers are, what I saw was happen on this forum earlier, etc.. They all are true enthusiasts of the engine modification, they are human first, and they got much more results than me, so I think we have to show respect first, and to solve any problems just personally. So I ask everybody to stop talking about mr.Roman, I still listen to him no matter what.

[Pcxdemon]

I'm more interested in the supplier, as I believe only Roman from RzRacing offers the 190cc kit, and he also uses the Kitaco i-Map for it.

I-map is very limited how much you can increase the fuel up. Unless you have bought additional Pc interface so you can edit fuel values and even then if you're novice about attempting that adjustment then forget about it. Takegawa has way more adjustment available by just turning the screw clock wise. Much better and simpler way to deal with..